https://habrahabr.ru/company/flant/blog/326414/

https://github.com/CrunchyData/postgres-operator
https://habrahabr.ru/post/301370/

2022
https://medium.com/swlh/advanced-kubernetes-operators-development-988edad5f58a
    https://habr.com/ru/company/southbridge/blog/691878/
2021
https://spring.io/blog/2021/11/19/get-to-know-a-kubernetes-operator